1. Field of the Invention
This invention relates to centrifugal pumps of the industrial type and specifically relates to providing an assembly of components for converting a centrifugal pump having a vortex-type impeller to a centrifugal pump having a spiral-type impeller for expanding the usefulness of the pump and increasing pump operation.
2. Description of Related Art
Centrifugal pumps are used in many industries to pump either clear water or slurries, the latter of which contain both fluid and solid components. The solids content of slurries vary in type and size, but all slurries are abrasive to some degree on the components of the pump. Therefore, centrifugal pumps are structured with varying abilities to withstand the varying degrees of abrasiveness of slurries. Pumps are consequently selected for their ability to process slurries of a given abrasiveness.
A centrifugal pump of the vortex type is one example of a slurry pump that is particularly constructed to process very abrasive slurries. The impeller of a vortex pump is made of very hard metal materials to withstand highly abrasive types of slurries. The impeller is particularly shaped to receive the influent slurry so that the solids content is processed by the impeller in a manner that reduces the impact of the solids on the impeller, thereby lessening the degradation of the impeller. The impeller may be configured with recessed areas between the impeller vanes which further contribute to the ability to process the slurry while lessening the impact of the solids on the impeller. Such impellers are known as recessed vortex impellers.
While vortex impellers are well-suited for their intended purpose, it is a natural consequence of the construction of vortex impellers, especially recessed vortex impellers, that certain pump efficiency is sacrificed due to the fact that the impeller is recessed from the main flow path of the fluid entering the pump. Occasions arise where the nature of the slurry being processed in a given installation changes, such as in a municipal waste facility. While the vortex centrifugal pump that is installed in the facility may still be operational, the fact that a vortex pump is less efficient than other types of centrifugal pumps becomes problematic to the optimal operation of the plant. In many instances, the vortex pump may be shut down and the installation modified to bypass the vortex pump in favor of processing the influent in a more efficient manner.
Thus, it would be beneficial in processing industries to provide a means by which a less efficient vortex centrifugal pump may be converted to a more efficient type of centrifugal pump responsive to a change in the type of slurries being processed, and in doing so employ the same pump casing and drive system of the existing vortex centrifugal pump to avoid having to replace the entire pump or having to modify the entire installation, both of which are extremely costly to plant operation.